ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Protea postharvest black leaf. A problem in search of a solution.

Paull, R. E.; Dai, J. W.;

Acta Horticulturae Year: 1990 Issue: No. 264 Pages: 93-101 Ref: 14 ref.

1990

บทคัดย่อ

It has been proposed that postharvest blackening of Protea neriifolia leaves is caused by water stress and/or insufficient carbohydrate supply. Experiments showed that the rate of development of leaf blackening varied with clonal source, season, and developed sooner in flowers harvested at the closed bud stage, with the slowest rate occurring in flowers harvested when the flower bracts had just started to unfold. Leaves were slower to blacken if harvested in the afternoon than in the early morning. The immediate removal of field heat from flowers was only worthwhile if low temperature was maintained until the flowers reached the wholesale or retail market. High postharvest light intensities, the use of preservative solutions containing sugar and, flower girdling and removal significantly delayed the onset of leaf blackening. Water uptake by flowers rapidly declined after harvest with the commercial preservative solutions delaying the rate of decline in uptake. The decline in water uptake paralleled the loss in flower fresh weight. Preharvest irrigation regime did not significantly influence postharvest leaf blackening rate. The effect of flower carbohydrate supply on leaf blackening was modified by flower stem water uptake ability.